﻿/*
 * [The "BSD licence"]
 * Copyright (c) 2005-2008 Terence Parr
 * All rights reserved.
 *
 * Conversion to C#:
 * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

namespace Antlr3.Misc
{
    using MethodImpl = System.Runtime.CompilerServices.MethodImplAttribute;
    using MethodImplOptions = System.Runtime.CompilerServices.MethodImplOptions;

    /**A very simple barrier wait.  Once a thread has requested a
     * wait on the barrier with waitForRelease, it cannot fool the
     * barrier into releasing by "hitting" the barrier multiple times--
     * the thread is blocked on the wait().
     */
    public class Barrier
    {
        protected int threshold;
        protected int count = 0;

        public Barrier( int t )
        {
            threshold = t;
        }

        [MethodImpl( MethodImplOptions.Synchronized )]
        public void WaitForRelease()
        {
            count++;
            // The final thread to reach barrier resets barrier and
            // releases all threads
            if ( count == threshold )
            {
                // notify blocked threads that threshold has been reached
                Action(); // perform the requested operation
                NotifyAll();
            }
            else
            {
                while ( count < threshold )
                {
                    Wait();
                }
            }
        }

        private void Wait()
        {
            throw new System.NotImplementedException();
        }

        private void NotifyAll()
        {
            throw new System.NotImplementedException();
        }

        /** What to do when everyone reaches barrier */
        public virtual void Action()
        {
        }
    }
}
